U.S. patent number 10,326,349 [Application Number 15/798,512] was granted by the patent office on 2019-06-18 for magnetic linear actuator.
This patent grant is currently assigned to EATON INTELLIGENT POWER LIMITED. The grantee listed for this patent is EATON CORPORATION. Invention is credited to Mark A. Juds, Anthony T. Ricciuti.
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United States Patent |
10,326,349 |
Ricciuti , et al. |
June 18, 2019 |
Magnetic linear actuator
Abstract
A magnet linear actuator includes a first element and an
armature situated on a support, with the armature being movable
along a movement axis between a first position engaged with the
first element and the second position spaced away from the first
element along the movement axis. The actuator further includes a
biasing element that biases the armature in a direction generally
toward the second position. The first element or the armature is
pivotable with respect to the other between a first orientation and
a second orientation. In the first orientation, the first element
and the armature have a first magnetic attraction to one another
that is sufficient to overcome the bias of the biasing element and
to retain the armature in the first position. In the second
orientation, the first element and the armature have either a
magnetic repulsion to one another or a weaker second magnetic
attraction.
Inventors: |
Ricciuti; Anthony T. (Bethel
Park, PA), Juds; Mark A. (New Berlin, WI) |
Applicant: |
Name |
City |
State |
Country |
Type |
EATON CORPORATION |
Cleveland |
OH |
US |
|
|
Assignee: |
EATON INTELLIGENT POWER LIMITED
(Dublin, IE)
|
Family
ID: |
66244369 |
Appl.
No.: |
15/798,512 |
Filed: |
October 31, 2017 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20190131861 A1 |
May 2, 2019 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01F
7/04 (20130101); H01F 7/17 (20130101); H02K
41/033 (20130101); H01F 7/1615 (20130101) |
Current International
Class: |
H02K
41/02 (20060101); H02K 41/03 (20060101) |
Field of
Search: |
;310/12.25,15,20-21,37 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lam; Thanh
Attorney, Agent or Firm: Eckert Seamans
Claims
What is claimed is:
1. A magnetic linear actuator structured for use in a device, the
magnetic linear actuator comprising: a support; a first element
situated on the support; an armature that is movable with respect
to the support along a movement axis between a first position
engaged with the first element and a second position spaced away
from the first element along the movement axis; a biasing element
that biases the armature in a direction generally toward the second
position; and at least a portion of one of the first element and
the armature being pivotable with respect to the other of the first
element and the armature between a first orientation and a second
orientation, in the first orientation the first element and the
armature having a first magnetic attraction to one another
sufficient to overcome the bias of the biasing element and
retaining the armature in the first position, in the second
orientation the first element and the armature having one of a
magnetic repulsion from one another and a second magnetic
attraction to one another that is weaker than the first magnetic
attraction and that is overcome by the bias of the biasing element
to cause the biasing element to move the armature toward the second
position.
2. The magnetic linear actuator of claim 1 wherein at least one of
the first element and the armature comprises a permanent
magnet.
3. The magnetic linear actuator of claim 2 wherein the first
element comprises a first plate that is formed of a ferromagnetic
material and that has a number of elevated portions and a number of
recessed portions situated thereon, and wherein one of the first
element and the armature comprises a second plate that is formed of
a ferromagnetic material and that has another number of elevated
portions and another number of recessed portions situated thereon,
one of the first plate and the second plate being movable with
respect to the other of the first plate and the second plate
between the first orientation and the second orientation, in the
first orientation the number of elevated portions and the another
number of elevated portions confronting one another and the number
of recessed portions and the another number of recessed portions
confronting one another, in the second orientation the number of
elevated portions confronting the another number of recessed
portions and the another number of elevated portions confronting
the number of recessed portions.
4. The magnetic linear actuator of claim 3 wherein the armature
comprises the second plate.
5. The magnetic linear actuator of claim 4 wherein the first plate
is situated between the second plate and the permanent magnet in
the first position of the armature.
6. The magnetic linear actuator of claim 3 wherein the first
element comprises the second plate, one of the first plate and the
second plate being rotatable with respect to the other of the first
plate and the second plate to move between the first orientation
and the second orientation.
7. The magnetic linear actuator of claim 3 wherein the permanent
magnet is situated on one of the first element and the armature and
comprises a plurality of magnet elements positioned adjacent one
another along a path and whose poles that face generally toward the
other of the first element and the armature alternate between NORTH
and SOUTH along the path.
8. The magnetic linear actuator of claim 7 wherein the second plate
is situated on the armature, and wherein the permanent magnet is
situated one of: on the first element, with the NORTH poles being
situated adjacent one of the number of elevated portions and the
number of recessed portions and the SOUTH poles being situated
adjacent the other of the number of elevated portions and the
number of recessed portions, and on the armature, with the NORTH
poles being situated adjacent one of the another number of elevated
portions and the another number of recessed portions and the SOUTH
poles being situated adjacent the other of the another number of
elevated portions and the another number of recessed portions.
9. The magnetic linear actuator of claim 7 wherein the path is
circular in shape.
10. The magnetic linear actuator of claim 3 wherein the support is
formed at least in part of a ferromagnetic material and comprises a
first wall upon which the first element is situated, a number of
lateral walls that extend from the first wall, and a second wall
situated on the number of lateral walls opposite the first wall and
having an opening formed therein through which the armature is
movable between the first and second positions.
11. The magnetic linear actuator of claim 10 wherein the armature
is formed of a ferromagnetic material.
12. The magnetic linear actuator of claim 2 wherein the permanent
magnet is circular in shape.
13. The magnetic linear actuator of claim 1 wherein the first
element comprises a number of permanent magnets and a number of
ferromagnetic elements, and wherein the armature comprises another
number of permanent magnets and another number of ferromagnetic
elements, in the first orientation the number of permanent magnets
and the another number of ferromagnetic elements confronting one
another and the another number of permanent magnets and the number
of ferromagnetic elements confronting one another to provide the
first magnetic attraction, in the second orientation the number of
permanent magnets confronting the another number of permanent
magnets to provide the magnetic repulsion from one another.
14. The magnetic linear actuator of claim 1 wherein the at least
portion of the one of the first element and the armature is
pivotable about the movement axis between the first orientation and
the second orientation.
15. The magnetic linear actuator of claim 1 wherein the first
element comprises a permanent magnet that comprises a plurality of
magnet elements positioned adjacent one another along a path and
whose poles that face generally toward the armature alternate
between NORTH and SOUTH along the path, and wherein the armature
comprises another permanent magnet that comprises another plurality
of magnet elements positioned adjacent one another along another
path and whose poles that face generally toward the first element
alternate between NORTH and SOUTH along the another path.
16. The magnetic linear actuator of claim 15 wherein in the second
orientation the NORTH poles of the plurality of magnet elements
confront the NORTH poles of the another plurality of magnet
elements and the SOUTH poles of the plurality of magnet elements
confront the SOUTH poles of the another plurality of magnet
elements to provide the magnetic repulsion from one another.
17. The magnetic linear actuator of claim 16 wherein the first
element comprises a plate that is formed of a ferromagnetic
material, permanent magnet being situated on the plate, and wherein
the armature comprises another plate that is formed of a
ferromagnetic material, the another permanent magnet being situated
on the another plate, the permanent magnet and the another
permanent magnet confronting one another in the first position.
18. The magnetic linear actuator of claim 16 wherein in the first
orientation the NORTH poles of the plurality of magnet elements
confront the SOUTH poles of the another plurality of magnet
elements and the NORTH poles of the another plurality of magnet
elements confront the SOUTH poles of the plurality of magnet
elements to provide the first magnetic attraction.
19. The magnetic linear actuator of claim 15 wherein the path and
the another path are each circular in shape.
20. The magnetic linear actuator of claim 1 wherein one of the
first element and the armature comprises a magnetic actuator that
is structured to pivot the at least portion of the one of the first
element and the armature between the first orientation and the
second orientation.
Description
BACKGROUND
Field
The disclosed and claimed concept relates generally to electronic
devices and, more particularly, to a magnetic linear actuator.
Related Art
Electromagnetic actuators are devices commonly found in power
equipment and provide working motion via of an internal
electromagnetic field, with the motion of the actuator providing a
control or switching function in such power equipment.
Electromagnetic actuators provide the movement used for actuation
by exposing a free moving plunger or armature to the magnetic field
created by energizing a static wire coil. The field attracts the
plunger or armature which resultantly moves with respect to the
field, thus providing the required actuation. Varying degrees of
actuation functionality can be achieved with an electromagnetic
actuator, ranging from simple single-cycle, single-speed actions to
fairly sophisticated control of both actuation time and
positioning.
One type of commonly used electromagnetic actuator is a permanent
magnet actuator, which makes use of one or more permanent magnets
and electric energy to control positioning of a plunger therein.
Permanent magnet actuators may be configured such that the plunger
thereof is held at a stroke position due to the permanent magnet,
with electricity being applied to the wire coil to move the plunger
to a different stroke position.
In such permanent magnet actuators, the wire coil typically is
employed to move the armature to a first position in proximity to
the permanent magnet and to overcome the bias of a return spring
that biases the armature in a direction generally away from the
permanent magnet. When it is desired to move the armature away from
the permanent magnet to move the armature to a second position
spaced from the first position, the wire coil typically is
energized with a reverse polarity so that its magnetic field
counteracts that of the permanent magnet, which resultantly permits
the bias of the return spring to overcome the partially
counteracted magnet attraction of the permanent magnet. It is
noted, however, that the energy that is used to power the wire coil
in order to move the armature away from the permanent magnet is
typically stored in large capacitors, and the charge necessary to
energize the wire coil sometimes can be absent if the charge
therein has been dissipated due to non -use of the actuator for an
extended period of time. In such an event, significant forces are
typically required to be applied to the armature in order to
overcome the magnetic attraction of the permanent magnet. Such
forces can be difficult to apply, and the need to apply them is
undesirable in a situation where a rapid movement of the armature
away from the permanent magnet is needed, such as in order to
switch a circuit breaker from an ON position to an OFF position in
a hurry. Improvements thus would be desirable.
SUMMARY
An improved magnet linear actuator includes a first element and an
armature situated on a support, with the armature being movable
along a movement axis between a first position engaged with the
first element and the second position spaced away from the first
element along the movement axis. The actuator further includes a
biasing element that biases the armature in a direction generally
toward the second position. One of the first element and the
armature is pivotable with respect to the other between a first
orientation and a second orientation. In the first orientation, the
first element and the armature have a first magnetic attraction to
one another that is sufficient to overcome the bias of the biasing
element and to retain the armature in the first position. In the
second orientation, the first element and the armature have either
a magnetic repulsion to one another or a second magnetic attraction
to one another that is weaker than the first magnetic attraction
that is overcome by the bias of the biasing element. The armature
is thus caused to move to the second position upon movement from
the first orientation to the second orientation.
In one embodiment, the first element includes a permanent magnet,
and the first element and the armature both include plates having
elevated portions and recessed portions that alternate, with one
another along a circular perimeter of the plates. In the first
orientation, the elevated portions of one plate are in a
confronting relationship with the elevated portions of the other
plate, which thereby result in a large magnetic flux from the
permanent magnet through the armature and which results in a first
magnetic attraction. When one of the plates is rotated with respect
to the other from the first orientation to the second orientation,
the elevated portions of one plate confront the recessed portions
of the other plate and vice versa, thus resulting in a second
magnetic attraction weaker than the first magnetic attraction and
which is overcome by the bias of the biasing element to move the
armature from the first position to the second position.
In another embodiment, first and second ferromagnetic plates having
alternating elevated and recessed portions are provided on a first
element that additionally includes a permanent magnet. The armature
is separate from the plates. In the first orientation when elevated
portions of one plate confront elevated portions of the other plate
and recessed portions of one plate confront recessed portions of
the other plate, magnetic flux through the armature results in a
first magnetic attraction that retains the armature in the first
position. When one of the plates is rotated from the first
orientation to the second orientation with respect to the other
plate, the elevated portions of one plate confront recessed
portions of another plate and vice versa to result in lessened
magnetic flux through the armature and a second magnetic attraction
that is weaker than the first magnetic attraction to permit the
biasing element to overcome the weaker magnetic attraction and to
move the armature toward the second position.
In another embodiment, a first element includes a permanent magnet
having a plurality of magnet elements positioned adjacent one
another along a circular perimeter of the permanent magnet and
whose poles that face generally toward the armature have
alternating NORTH and SOUTH poles along the perimeter. The NORTH
and SOUTH alternating poles of the magnet elements are aligned with
alternating elevated and recessed portions on a ferromagnetic first
plate that is situated adjacent the permanent magnet. The armature
includes another ferromagnetic plate that likewise has alternating
elevated and recessed portions. In the first orientation, the
elevated portions of one plate confront the elevated portions of
the other plate, and the recessed portions of both plates likewise
are confronting to result in a first magnetic attraction due to
magnetic flux from the magnet elements of the permanent magnet
flowing through the two plates. When one of the plates is rotated
from the first orientation to a second orientation, the elevated
portions of one plate confront the recessed portions of the other
plate and vice versa, thus resulting in a second magnetic
attraction within the plates that is weaker than the first magnetic
attraction, which thus is overcome by the bias of the biasing
element to move the armature away from the first position and
toward the second position.
In another embodiment, the first portion includes a first plate
upon which are situated a number of magnetic elements and a number
of ferromagnetic elements that are alternately positioned along a
circular path. The armature likewise includes a base having
magnetic elements and ferromagnetic elements that are alternately
positioned along another circular path thereon. When the first
plate and the base are in the first orientation, the magnetic
elements of the first element are confronting with and are
magnetically attracted with the ferromagnetic elements of the
armature, and vice versa. When one of the first elements and the
armature is pivoted from the first position to the second position,
the magnetic elements of the first element are in a confronting
relationship with the magnetic elements of the armature, and such
confronting magnetic elements are of similar polarity, to thus
result in a mutual magnetic repulsion between the first portion and
the armature in the second orientation which results in movement of
the armature toward the second position by operation of the biasing
element connected therewith.
In another embodiment, the first element includes a permanent
magnet having a plurality of magnet elements that are positioned
along the circular path and whose poles that face generally toward
the armature alternate between NORTH and SOUTH along the path.
Likewise, the armature includes another permanent magnet having
another set of magnet elements positioned along another circular
path and whose poles that face generally toward the first element
alternate between NORTH and SOUTH along the path. In the first
orientation, the NORTH poles of the first element are in a
confronting relationship with the SOUTH poles of the armature, and
vice versa. When the armature is pivoted from the first orientation
to the second orientation, the NORTH poles of the first element and
the armature confront one another, and the SOUTH poles of the first
element and the armature likewise confront one another to result in
a mutual magnetic repulsion of the first element and the armature.
This results in movement of the armature toward the second position
and biasing by the biasing element of the armature to the second
position.
Accordingly, an aspect of the disclosed and claimed concept is to
provide an improved magnetic linear actuator which, in a first
orientation, retains an armature in a first position engaged with a
first portion and which, in a second orientation rotated from the
first orientation, the armature is caused to move away from the
first portion toward a second position along a movement axis.
As such, an aspect of the disclosed and claimed concept is to
provide an improved magnetic linear actuator structured for use in
a device. The magnetic linear actuator can be generally stated as
including a support, a first element situated on the support, an
armature that is movable with respect to the support along a
movement axis between a first position engaged with the first
element and a second position spaced away from the first element
along the movement axis, a biasing element that biases the armature
in a direction generally toward the second position, and at least a
portion of one of the first element and the armature being
pivotable with respect to the other of the first element and the
armature between a first orientation and a second orientation, in
the first orientation the first element and the armature having a
first magnetic attraction to one another sufficient to overcome the
bias of the biasing element and retaining the armature in the first
position, in the second orientation the first element and the
armature having one of a magnetic repulsion from one another and a
second magnetic attraction to one another that is weaker than the
first magnetic attraction and that is overcome by the bias of the
biasing element to cause the biasing element to move the armature
toward the second position.
BRIEF DESCRIPTION OF THE DRAWINGS
A further understanding of the disclosed and claimed concept can be
gained from the following Description when read in conjunction with
the accompanying drawings in which:
FIG. 1 is a side schematic view of a magnetic linear actuator in
accordance with a first embodiment of the disclosed and claimed
concept in a first orientation and with an armature thereof in a
first position;
FIG. 1A is front elevational view of a permanent magnet of the
actuator of FIG. 1;
FIG. 2 is a view similar to FIG. 1, except depicting the actuator
in a second orientation and depicting the armature in a second
position;
FIG. 3 is a schematic side depiction of an improved actuator in
accordance with a second embodiment of the disclosed and claimed
concept in a first orientation and with an armature thereof in a
first position;
FIG. 3A is a front elevational view of a permanent magnet of the
actuator of FIG. 3;
FIG. 4 is a view similar to FIG. 3, except depicting the actuator
in a second orientation and with the armature in a second
position;
FIG. 5 is a schematic side depiction of an improved actuator in
accordance with a third embodiment of the disclosed and claimed
concept in a first orientation and with an armature thereof in a
first position;
FIG. 5A is a front elevational view of a permanent magnet of the
actuator of FIG. 3;
FIG. 6 is a view similar to FIG. 5, except depicting the actuator
in a second orientation and with the armature in a second
position;
FIG. 7 is a schematic depiction of a magnetic linear actuator in
accordance with a fourth embodiment of the disclosed and claimed
concept;
FIG. 8 is a schematic side depiction of an improved actuator in
accordance with a fifth embodiment of the disclosed and claimed
concept in a first orientation and with an armature thereof in a
first position;
FIG. 8A is a front elevational view of a permanent magnet of the
actuator of FIG. 8;
FIG. 9 is a view similar to FIG. 8, except depicting the actuator
in a second orientation and with the armature in a second
position;
FIG. 10 is another schematic depiction of the actuator of FIG. 8 in
the first orientation and depicting a lever arm and a magnetic
actuator that can be employed to perform the rotation from the
first orientation to the second orientation.
Similar numerals refer to similar parts throughout the
specification.
DESCRIPTION
An improved actuator 4 in accordance with the disclosed and claimed
concept is depicted schematically in FIGS. 1 and 2 and is depicted
in part in FIG. 1A. The actuator 4 is a magnetic linear actuator
that is mounted to a device 6 in order to perform some operation on
the device 6. For example, the device 6 may be a circuit
interruption device, and the actuator 4 may be installed therein
and operable to switch the circuit interruption device between an
ON condition and an OFF condition, by way of example. The exemplary
actuator 4 can be said to include a support 10 that is mounted to
the device 6 and to further include a first element 12 that is
situated on the support 10. The actuator 4 further includes an
armature 16 that is movably situated on the support 10 and is
movable along a movement axis 18 between a first position engaged
with the first element 12, such as is depicted generally in FIG. 1,
and a second position spaced along the movement axis 18 away from
the first element 12, such as is depicted generally in FIG. 2. The
actuator 4 further includes a biasing element 22 that is mounted to
the armature 16 and which biases the armature 16 in a direction
generally away from the first position and toward the second
position. The biasing element 22 thus biases the armature 16 in a
biasing direction 24, which is a direction along the movement axis
18 away from the first element 12. While the biasing element 22 is
expressly depicted herein in FIG. 1, it is noted that other
embodiments of actuators that are set forth herein below likewise
include a similar biasing element, although for the sake of
simplicity such other biasing elements are not expressly depicted
herein. Rather, the biasing direction in which the biasing element
biases the corresponding armature is depicted in the other drawings
presented herein.
The support 10 can be said to include a first wall 28, a number of
lateral walls 30 connected with the first wall 28, and a second
wall 34 connected with a number of lateral walls 30. As employed
herein, the expression "a number of" and variations thereof shall
refer broadly to any non-zero quantity, including a quantity of
one. The second wall 34 has an opening 36 formed therein, and the
armature 16 is movably situated on the support 10 and is movable
through the opening 36. The support 10 is formed of a ferromagnetic
material such as iron or steel, by way of example.
The actuator 4 further includes a coil 38 that is situated within
an interior region 39 of the support 10 and is situated adjacent
the number of lateral walls 30. As is generally understood in the
relevant art, the coil 38 is energized with a first polarity in
order to cause the armature 16 to move from the second position to
the first position. Once in the first position, such as is depicted
generally in FIG. 1, a first magnetic attraction between the first
element 12 and the armature 16 that will be described in greater
detail below is sufficiently strong that it overcomes the bias of
the biasing element 22, thus retaining the armature 16 in the first
position that is depicted generally in FIG. 1. When it is desired
to move the armature 16 from the first position of FIG. 1 to the
second position of FIG. 2, the coil 38 can be energized with an
opposite polarity which at least partially counteracts the first
magnetic attraction to result in a second magnetic attraction
between the first element 12 and the armature 16 that is weaker
than the first magnetic attraction and which is overcome by the
biasing element 22 and which results in the armature 16 being moved
by the biasing element 22 in a direction away from the first
position of FIG. 1 and toward the second position of FIG. 2.
More particularly, the first element 12 includes a permanent magnet
42 that is depicted in FIGS. 1-2 as being of a circular shape and
as having a NORTH pole 44 and a SOUTH pole 48 opposite one another.
The first element 12 further includes a first plate 50 that is of a
circular configuration and which includes a number of elevated
portions 52 that are pie-wedge-shaped and which are formed on a
face of the plate 50 that is situated opposite the permanent magnet
42. It is noted that the edges of the elevated portions 52, i.e.,
at the transitions between the elevated portions 52 and the
recessed portions 56, can be vertical or angled. The first plate 50
further includes a number of recessed portions 56 that are situated
between adjacent elevated portions 52 such that the elevated
portions 52 and the recessed portions 56 can be said to alternate
with one another about a perimeter of the first plate 50. The first
plate 50 is likewise formed of a ferromagnetic material. As can be
understood from FIGS. 1 and 2, the permanent magnet 42 is
interposed between the first plate 50 and the first wall 28.
The armature 16 can be said to include an elongated body 58 and to
further include a base 62 that is situated at an end of the body
58. The body 58 is movable through the opening 36 when the armature
16 moves between the first and second positions. The armature 16
further includes a second plate 64 situated on the base 62 and
formed of a ferromagnetic material. It is noted that the second
plate 64 and the base 62 can be formed as a single plate. In a
fashion to the first plate 50, the second plate 64 includes a
number of elevated portions 68 that are of a wedge-shaped
configuration and further includes a number of recessed portions 70
that are situated between adjacent elevated portions 68. It is
noted that the edges of the elevated portions 68, i.e., at the
transitions between the elevated portions 68 and the recessed
portions 70, can be vertical or angled.
In the depicted exemplary embodiment, the armature 16, in addition
to being translatable along the movement axis 18 between the first
position of FIG. 1 and the second position of FIG. 2, is pivotable
about the movement axis 18 between a first orientation with respect
to the first element 12, as is depicted generally in FIG. 1, and a
second orientation with respect to the first element 12, as is
depicted generally in FIG. 2. In the first orientation, the
elevated portions 52 of the first plate 50 are in a confronting
relationship with the elevated portions 68 of the second plate 64.
Further in the first orientation, the recessed portions 56 of the
first plate 50 are in a confronting relationship with the recessed
portions 70 of the second plate 64. In such an orientation, the
permanent magnet 42 induces magnetic flux, as indicated by the
magnetic flux lines 74, in the first and second plates 50 and 64
and in the support 10 and the body 58 and the base 62. All of the
various magnetic flux lines are indicated at the numeral 74. As can
be understood from FIG. 1, the confronting relationship of the
elevated portions 52 with the elevated portions 68 facilitates the
development of strong magnetic flux through the various
ferromagnetic portions of the actuator 4 such as are noted above,
it being further noted that the armature 16 itself is formed of a
ferromagnetic material. Such strong magnetic flux results in a
first magnetic attraction between the first element 12 and the
armature 16.
As can be understood from FIG. 2, however, the armature 16 has
rotated with respect to the first element 12, with such rotation
being indicated at the numeral 76. The exemplary rotation between
the first and second orientations is 45 degrees. In the second
orientation of FIG. 2, it can be seen that the recessed portions 56
of the first plate 50 are in a confronting relationship with the
elevated portions 68 of the second plate 64, and the elevated
portions 52 of the first plate 50 are in a confronting relationship
with the recessed portions 70 of the second plate 64. Such an
arrangement of the first and second plates 50 and 64 with respect
to one another causes the magnetic flux lines 74 between the first
and second plates 50 and 64 to move in an oblique direction with
respect to, for instance, the magnetic flux lines 74 that are in
the body 58 and the number of lateral walls 30, thus decreasing the
overall magnetic flux through the body 58 and resulting in a
second, reduced magnetic attraction between the armature 16 and the
first element 12. Such reduced magnetic attraction between the
first element 12 and the armature 16 is insufficient to overcome
the bias of the biasing element 22, with the result that the
positioning of the armature 16 in the second orientation of FIG. 2
results in the biasing element 22 biasing and moving the armature
16 in the biasing direction 24 in a direction generally away from
the first element 12 and toward the second position of FIG. 2.
While the actuator 4 in the first orientation of FIG. 1 had a first
magnetic attraction between the first element 12 and the armature
16 that was sufficient to overcome the bias of the biasing element
22, the actuator 4 in the second orientation of FIG. 2 has a second
magnetic attraction between the first element 12 and the armature
16 that is weaker than the first magnetic attraction and that is
insufficient to overcome the bias of the biasing element 22. As
such, the biasing element 22 moves the armature 16 to the second
position of FIG. 2.
While the exemplary actuator 4 is depicted herein as moving between
the first and second orientations as a result of rotating the
armature 16 about the movement axis 18 with respect to the first
element 12, it is understood that the actuator 4 in other
embodiments could move between the first and second orientations by
instead rotating the first plate 50 of the first element 12 about
the movement axis 18 with respect to the armature 16. The amount of
rotation about the movement axis 18 that results in movement
between the first and second orientations depends upon the
configurations of the first and second plates 50 and 64. For
instance, if the first and second plates 50 and 64 each include
four of the elevated portions 52 and 68 and four instances of the
recessed portions 56 and 70, with each of the elevated and recessed
portions 52, 56, 68, and 70 occupying a 45.degree. sector of the
first and second plates 50 and 64, the rotation about the movement
axis that will result in a change between the first orientation and
the second orientation will likewise be 45.degree.. It is
understood that the bias of the biasing element 22 might overcome
the reduced magnetic flux before the armature 16 is fully rotated
the 45.degree.. Likewise, if a greater number of elevated and
recessed portions 52, 56, 68, and 70 are formed on the first and
second plates 58 and 64, a correspondingly reduced rotation in the
rotation direction 76 will result in movement of the actuator 4
between the first and second orientations, and vice versa. As can
be understood from FIGS. 1 and 2, the first and second plates 50
and 64 have the same number of elevated and recessed portions 52,
56, 68, and 70, and they are of the same relative size and
shape.
Any structures can be employed to perform the rotation between the
first and second orientations. For instance, FIG. 10 depicts a
magnetic actuator 480 that is connected via a lever arm 484 to the
rotatable portion of another actuator in accordance with another
embodiment that will be described in greater detail below, and it
is understood that such an arrangement is usable in conjunction
with any of the embodiments of the actuators that are set forth
herein, including the actuator 4.
In order to return the rotatable structure from the second
orientation back to the first orientation, a return spring may be
provided, if necessary. It is also understood, however, that when
returning the armature 16, for instance, from the second position
of FIG. 2 back to the first position of FIG. 1, the first and
second plates 50 and 64 will magnetically naturally self-align to
the first orientation such as is depicted generally in FIG. 1. As
such, it may not be strictly necessary to provide a return spring
or other return device since the magnetic properties of the
actuator 4 will return the rotating structures from the second
orientation to the first orientation when the armature 16 is moved
from the second position back to the first position.
It thus can be seen that by rotating a rotatable structure from the
first orientation of FIG. 1 to the second orientation of FIG. 2, a
relatively small amount of force at a distance, i.e., a torque, is
required to release the armature 16 from the first position of FIG.
1 to the second position of FIG. 2. That is, the relatively small
amount of torque that moves the armature 16 between the first and
second orientations results in a reduction in the magnetic
attraction between the first element 12 and the armature 16
sufficient that the biasing element 22 overcomes the reduced
magnetic attraction and moves the armature 16 to the second
position of FIG. 2. While the coil 38 need not be employed in order
to move the armature 16 from the first position of FIG. 1 to the
second position of FIG. 2, the coil 38 is nevertheless provided in
order to move the armature 16 from the second position back to the
first position of FIG. 1. Such rotation of the armature 16 can be
performed by the magnetic actuator 480, such as is depicted
generally in FIG. 10 in conjunction with a different embodiment of
an actuator that will be described herein below in greater detail,
or such rotation can be performed manually depending upon the needs
of the particular application.
An improved actuator 104 in accordance with a second embodiment of
the disclosed and claimed concept is depicted in FIGS. 3-4. The
actuator 104 is a magnetic linear actuator that is similar to the
actuator 4 inasmuch as the actuator 104 includes a support 110, a
first element 112, and an armature 116. The armature 116 is movable
along a movement axis 118 between a first position such as is
depicted generally in FIG. 3 and a second position such as is
depicted generally in FIG. 4. The armature 116 is biased by a
biasing element in a biasing direction 124 toward the second
position. The first element 112 includes a permanent magnet 142
that is of a circular configuration, such as is depicted generally
in FIG. 3A, and further includes a first plate 150 that is of a
circular configuration and which includes a number of elevated
portions 152 and a number of recessed portions 156. It is noted,
however, that the first element 112 further includes a base 162 and
a second plate 164 that are separate from a body 158 of the
armature 116. The second plate 168 is similar to the first plate
150 and includes a number of elevated portions 168 and a number of
recessed portions 170. It thus can be understood that the permanent
magnet 142, the first and second plates 150 and 164, and the base
162 function in the actuator 104 in a fashion similar to the way in
which the permanent magnet 42, the first and second plates 50 and
64, and the base 62 functioned in the actuator 4. It is understood,
however, that the second plate 164 and the base 162 are separate
from the armature 116 and are instead a first subassembly portion
of the first element 112. As such, the first subassembly portion of
the first element 112 is moving between a first orientation and a
second orientation, as is indicated at the numeral 176 in FIG. 4,
with respect to the first plate 150 of the first element 112. In
the depicted exemplary embodiment, the base 162 and the second
plate 164, which together constitute the first subassembly portion
of the first element 112, are pivoting between the first and second
orientations, but it is understood that in other embodiments the
first plate 150 instead could be pivoting between the first and
second orientations with respect to the base 162 and the second
plate 164.
As with the actuator 4, the first element 112 in its second
orientation results in the elevated portions 152 confronting the
recessed portions 170 and the recessed portions 156 confronting the
elevated portions 168. The result is magnetic flux lines (as
indicated at the numeral 174) that must travel in an oblique
direction with respect to the movement axis 118, and which results
in a reduced magnetic flux within the body 158. Such reduced
magnetic flux in the body 158 of the armature 116 results in the
bias element of the actuator 104 overcoming such reduced magnetic
attraction between the first element 112 and the armature 116
which, in turn, results in movement of the armature 116 in the
biasing direction 124, as is indicated generally in FIG. 4.
An improved actuator 204 in accordance with a third embodiment of
the disclosed and claimed concept is depicted generally in FIGS.
5-6. The actuator 204 includes structures that are similar to those
of the actuator 4 inasmuch as the actuator 204 includes a support
210, a first element 212, and an armature 216 that is movable along
a movement axis 218 between a first position such as is depicted
generally in FIG. 5 and a second position such as is depicted
generally in FIG. 6. The actuator 204 additionally includes a
biasing element that biases the armature 216 in a biasing direction
224. As with the actuator 4, the first element 212 includes a
permanent magnet 242 that is of a circular shape and a first plate
250 having elevated portions 252 and recessed portions 256. The
armature 216 includes an elongated body 258 and a base 262, and
further includes a second plate 264 situated on the base 262, with
the second plate 264 including a number of elevated portions 268
and a number of recessed portions 270. The first and second plates
250 and 264 are of the same configuration as those of the actuators
4 and 104.
It is noted, however, that the permanent magnet 242 is different
than those of the actuators 4 and 104 inasmuch as the permanent
magnet 242 is formed from a plurality of magnet elements 243 that
are distributed along a circular path 246 which, in the depicted
exemplary embodiment, could be said to extend along the circular
perimeter of the permanent magnet 242. The magnet elements 243 each
include a NORTH pole 244 and a SOUTH pole 248 opposite one another,
and the magnet elements 243 are arranged with respect to one
another such that the poles that face generally toward the armature
216 alternate between NORTH and SOUTH along the path 246, as can be
seen in FIG. 5A.
As can be understood from FIG. 5, when the actuator 204 is in the
first orientation of FIG. 5 with the alternate positioning of the
magnet elements 243 such that their NORTH and SOUTH poles 244 and
248 alternate with one another, the magnetic flux that results in
from the permanent magnet 242, as indicated by the magnetic flux
lines 274, flows largely through the permanent magnet 242, the
first and second plates 250 and 264, the base 262, and a platform
275 that is formed of a ferromagnetic material and that is a
structure upon which the permanent magnet 242 is situated. The
exemplary permanent magnet 242 is interposed between the platform
275 and first plate 250. Such magnetic flux results in a strong
first magnetic attraction between the first element 212 and the
armature 216 in the first orientation of FIG. 5.
As can be understood from FIG. 6, however, when the actuator 204 is
pivoted from the first orientation of FIG. 5 to the second
orientation of FIG. 6, such as through rotation of the armature 216
about the movement axis 218, as indicated at the arrow 276 in FIG.
6, the magnetic flux lines 274 largely cease to flow through the
second plate 264 and the base 262. Rather, the magnetic flux
instead flows through the permanent magnet 242, the platform 275,
and the first plate 250, and furthermore flows parallel with the
first plate 250 generally across the recessed portions 256. The
reduction in magnetic flux between the first element 212 and the
armature 216 as a result of pivoting the armature 216 from the
first orientation of FIG. 5 to the second orientation of FIG. 6
results in a second, reduced magnetic attraction between the first
element 212 and the armature 216. That is, in the first orientation
of FIG. 5, the magnetic flux lines 274 travel through the first
element 212 and also through the base 262 and second plate 264 of
the armature 216, which results in a first magnetic attraction
between the first element 212 and the armature 216 that is
relatively strong. However, by causing the elevated portions 252 to
confront the recessed portions 270 and causing the recessed
portions 256 to confront the elevated portions 268, this results in
the magnetic flux lines 274 flowing across the recessed portions
256 rather than flowing into the armature 216. This results in the
second, reduced magnetic attraction between the first element 212
and the armature 216, which results in the biasing element of the
armature 216 overcoming such second magnetic attraction and moving
the armature 216 in the biasing direction 224 to the second
position of FIG. 6. This advantageously enables the support 210 and
the body 258 to be formed of a non -ferromagnetic material, if this
is desired. This could provide savings in weight and expense, along
with other savings. It is understood that the first element 212
could instead be pivoted between the first and second orientations
with respect to the armature 216 without departing from the spirit
of the instant disclosure.
An improved actuator 304 in accordance with a fourth embodiment of
the disclosed and claimed concept is depicted generally in FIG. 7.
The actuator 304 is a magnetic linear actuator having a support
310, a first element 312, and an armature 316. The first element
312 has a first plate 350 that is of a circular configuration and
is formed of a ferromagnetic material. The first element 312
further includes a number of first magnet elements 343 and a number
of first ferromagnetic elements 345 that are alternately positioned
about a circular first path 346 on the first plate 350. In a like
fashion, the armature 316 includes a base 362 having a number of
second magnet elements 363 and a number of second ferromagnetic
elements 369 alternately positioned along a second path 371 thereof
that is situated inboard of the perimeter of the base 362. The base
362 is formed of a ferromagnetic material, and other portions of
the armature 316 can likewise be formed of a non-ferromagnetic
material. Elements 344 may be formed as raised portions on plate
350 as a single part, and elements 363 may be formed as raised
portions on base 362 as a single part. It is noted that the first
plate 350 and the base 362 may be formed of a non-ferromagnetic
material, but this would result in significantly reduced magnetic
attraction forces.
As can be understood from FIG. 7, when the armature 316 is situated
adjacent the first element 312, a first magnetic element 343A of
the first magnet elements 343 will be situated in a confronting
relationship with a second ferromagnetic element 369A of the second
ferromagnetic elements 369. Likewise, a second magnet element 363A
of the second magnet elements 363 will be in a confronting
relationship with a first ferromagnetic element 345A of the first
ferromagnetic elements 345. Such confronting relationships will
result in magnetic attraction between the first magnet element 343A
and the second ferromagnetic element 369A and will further result
in magnetic attraction between the second magnet element 363A and
the first ferromagnetic element 345A. Such magnetic attractions
between magnet elements and ferromagnetic elements results in a
magnetic attraction between the first element 312 and the armature
316 to retain the armature 316 engaged with the first element 312
in the first orientation that is depicted in FIG. 7.
If the base 362 is rotated from the first orientation of FIG. 7 to
a second orientation, such as is indicated with the rotation arrow
376, the first magnet elements 343 and the second magnet elements
363 would be in a confronting relationship. Inasmuch as the poles
of the first magnet elements 343 that face toward the armature 316
are all NORTH poles 344, and inasmuch as the poles of the second
magnet elements 363 that face toward the first element 312 are
likewise NORTH poles 366, the confronting relationship of the NORTH
poles 344 and the 366 will result in a mutual magnetic repulsion
between the first element 312 and the armature 316. This will
result in the biasing element that biases the armature 316 in a
biasing direction 324 translating the armature 316 to a second
position spaced from the first element 312.
It can be understood that the attraction between a magnet and a
ferromagnetic element such as steel is nearly as strong as the
magnetic attraction between a magnet and another magnet. By
providing the first magnet elements 343 and the second magnet
elements 363 to be in a confronting relationship with steel first
and second ferromagnetic elements 345 and 369 in the first
orientation of the actuator 304, as is depicted in FIG. 7, a strong
magnetic attractive force can between the first element 312 and the
armature 316 results. However, by providing similar poles, i.e.,
the NORTH poles 344 and 366, in a confronting relationship in the
second orientation of the actuator, as is indicated at the arrow
376, such commonality of the confronting poles of the first and
second magnet elements 343 and 363 results in mutual magnetic
repulsion between the first portion 312 and the armature 316, thus
permitting the biasing element of the actuator 304 to move the
armature 316 along a movement axis to a second position spaced from
the first element 312. It is also understood that the first portion
312 can instead be pivoted between the first and second
orientations with respect to the armature 316 without departing
from the spirit of the instant disclosure. In the depicted
exemplary embodiment, a rotation of the armature 316 between the
first and second orientations is a rotation of sixty degrees,
although it is understood that the mutual repulsion may begin and
move the armature 316 before full rotation of sixty degrees is
reached.
An improved actuator 404 in accordance with a fifth embodiment of
the disclosed and claimed concept is depicted in FIGS. 8-10. The
actuator 404 is a magnetic linear actuator that includes a support
410, a first element 412 situated on the support 410, and an
armature 416 that is movably situated on the support 410. The
actuator 404 includes a permanent magnet 442 that is similar to the
permanent magnet 242 of the actuator 204. The permanent magnet 442
is situated on a platform 475 that is formed of a ferromagnetic
material and that is itself situated on the support 410. However,
the armature 416 includes another permanent magnet 461 that is
similar to the permanent magnet 242 and that is situated on a base
462 thereof. The base 462 is formed of a ferromagnetic
material.
FIG. 8A depicts the permanent magnet 442 as including a plurality
of first magnet elements 443 each having a NORTH pole 446 and a
SOUTH pole 448, with the first magnet elements 443 being arranged
such that the NORTH and SOUTH poles 446 and 448 alternate along a
circular path 446 which, in the depicted exemplary embodiment, is
the circular perimeter of the circular magnet 442. The other
permanent magnet 461, such as is depicted in FIG. 10, is similar
thereto inasmuch as it includes a plurality of second magnet
elements 463 each having a NORTH pole 466 and a SOUTH pole 467,
with the second magnet elements 463 being arranged about the second
path 471 such that the NORTH and SOUTH poles 466 and 467 alternate
in exactly the fashion of the permanent magnet 442 of FIG. 8A. When
the armature 416 is in the first position and the first orientation
of FIG. 8, the permanent magnets 442 and 461 are arranged such that
the NORTH poles 444 confront the SOUTH poles 467 and the NORTH
poles 466 confront the SOUTH poles 448 to thereby together provide
a strong first magnetic attraction between the first element 412
and the armature 416. As can be understood from FIG. 8, a number of
magnetic flux lines indicated at the numerals 474 extend between
the permanent magnets 442 and 461 and additionally pass through the
platform 475 and the base 462. The first magnetic attraction is
sufficiently strong to overcome the biasing element thereof that
biases the armature 416 in a biasing direction 424.
However, when the armature 416 is rotated as is indicated at the
arrow 476 in FIG. 9, the first and second magnet elements 443 and
463 are positioned with respect to one another such that the NORTH
poles 444 and the NORTH poles 466 confront one another and such
that the SOUTH poles 448 and the SOUTH poles 467 likewise confront
one another to result in mutual magnetic repulsion between the
first element 412 and the armature 416. This causes the armature
416 to move in the biasing direction 424 to the second position of
FIG. 9. As can be understood from FIGS. 8-9, the armature 416 is
rotated through an angle of approximately 45.degree. about a
movement axis 418 along which the armature 416 translates between
the first position of FIG. 8 and the second position of FIG. 9. It
is understood, however, that the actuator 404 can be configured
such that the first element 412 is movable between the first and
second orientations rather than the armature 416 being movable
between the first and second orientations. It is reiterated that
this is the case for the actuators 4, 204, and 304 as well.
As can be understood from FIG. 9, once the armature 416 has been
rotated from the first orientation of FIG. 8 to the second
orientation of FIG. 9, and the mutual magnetic repulsion between
the first element 412 and the armature 416 begins to move the
armature 416 away from the first element 412, the magnetic flux
between the permanent magnets 442 and 461 diminishes significantly,
and rather magnetic flux begins to flow between adjacent first
magnet elements 443 of the permanent magnet 442, and likewise
magnetic flux begins to flow between adjacent second magnet
elements 463 of the permanent magnet 461. This is indicated with
additional flux lines 474 in FIG. 9. The reduction in magnetic flux
between the permanent magnets 442 and 461 in the second orientation
causes the armature 416 to separate rapidly from the first element
412. That is, the armature 416 rapidly moves from its first
position in FIG. 8 engaged with the first element 412 in the first
orientation to the second position of FIG. 9 spaced away from the
first element 412.
As can be seen in FIG. 10, an exemplary magnetic actuator 480 is
usable to rotate the armature 416 between the first and second
orientations. In the example shown, the magnetic actuator 480 is
connected with a lever arm 484 such that a force supplied to the
lever arm 484 results in a torque being applied to the armature 416
to rotate it between the first and second orientations. Such a
force being applied to the lever arm 484 can instead be applied
manually if such an application is desirable depending upon the
particular needs of the given application. It is noted that the
same lever arm 484 and magnetic actuator 480 can be applied to any
of the actuators 4, 104, 204, and 304, depending upon the needs of
the given application, to pivot their movable portions between
their first and second orientations.
The actuator 404 further includes a stop 488 that is oriented such
that an engagement surface 492 is oriented at a 45.degree. angle
with respect to a surface of the lever arm 484 when the armature
416 is in the first orientation. It thus can be understood that
rotation of the armature 416 until the lever arm 484 engages the
engagement surface 492 of the stop 488 will result in the armature
416 being in the second orientation wherein the NORTH poles 444 and
466 confront one another and wherein the SOUTH poles 448 and 467
likewise confront one another to result in the aforementioned
mutual magnetic repulsion between the first element 412 and the
armature 416. The stop 488 can likewise be implemented into any of
the actuators 4, 104, 204, and 304 depending upon the needs of the
particular application. While the rotation of the armature 416
between the first and second orientations requires a rotation of
the armature 416 through an exemplary angle of 45.degree., it is
noted that if a greater or lesser number of first and second magnet
elements 443 and 463 is provided, the angle through which the
armature 416 will be moved is correspondingly going to be
changed.
Accordingly, it can be seen that the actuators 4, 104, 204, 304,
and 404 each provide a disengagement between the first element and
the armature thereof upon a relatively simple rotation of at least
a portion of the first element or the armature to permit the
biasing element thereof to bias the armature to cause the armature
to move to the second position spaced away from the first element,
such as to move the device 6 between one state and another. The
effort required to perform the rotation is relatively small and
need not necessarily rely upon a source of electricity. This is
highly advantageous since it facilitates the device 6 changing its
state. Other advantages will be apparent.
While specific embodiments of the disclosed concept have been
described in detail, it will be appreciated by those skilled in the
art that various modifications and alternatives to those details
could be developed in light of the overall teachings of the
disclosure. Accordingly, the particular arrangements disclosed are
meant to be illustrative only and not limiting as to the scope of
the disclosed concept which is to be given the full breadth of the
claims appended and any and all equivalents thereof.
* * * * *